Derby boss John Eustace confirmed new striker Rhian Brewster faces a race against time to make his Rams debut against Bristol City at Pride Park on Friday.
Brewster arrived from Sheffield United on a free transfer on 1 August but has struggled for fitness at the beginning of the campaign after missing pre-season.
“Rhian’s had four sessions with the group. He’s looking fitter, he played 45 minutes [for the B team] behind closed doors against Oxford,” Eustace told BBC Radio Derby.
“We’ll assess it on Friday, we’ll see how he’s feeling, we’ll see what the medical department say as well.
“It’s important we protect him and when he’s ready, he’ll be playing.
“Rhian is a top performer in the Championship. The club worked very hard over the summer to bring him in and it’s been a group effort to make sure he feels at home here at Derby.
“He’s going to get better throughout the season, for sure.”